Fifa may decide this month whether to allow teams to use a fourth substitute in extra time.
The International Football Association Board (Ifab) will meet to discuss the proposal in Northern Ireland on February 28.
Should a motion be passed the concept could take effect in July.
The idea, which has the support of Germany’s World Cup-winning coach Joachim Loew, is to help teams cope with tired and injured players in the extra 30 minutes of play.
Other items on the agenda include discussing potentially using video replays to assist referees, as well as whether to relax a “triple punishment” rule where a defender can make a challenge that results in a penalty kick, a red card and suspension.
Ifab includes delegates from Fifa and four British football associations.